1. Field of the Invention
This invention concerns improvements in and relating to monitoring of items, particularly, but not exclusively, the monitoring of radioactive emissions arising from elongate items such as pipe sections.
2. Present State of the Art
The technique described in WO98/38531 is useful for establishing the radioactive emission sources associated with different surfaces of an elongate item, such as a pipe section. It does so by placing the item in a chamber, moving air past the item and detecting ions. The ions are generated in the air when it is close to the item by the passage of emissions, predominantly alpha emissions, arising from radioactive sources associated with the item. An item is introduced into the chamber by opening one of the long walls of the chamber and lowering the item into the chamber, in a direction generally perpendicular to the item's axis. The item is mounted on a cradle and the chamber is then shut.
Problems with this approach arise from the difficulties in manoeuvring an elongate item in this way. These may include the time required and/or the risk of damage to the instrument through such an approach.